Switch mechanism for testing transformers



Oct. 29, 1929.

A. JOHANSEN SWITCH MECHANISM FOR TESTING TRANSFORMERS Fil'ed June.28, 1927 3 Sheets- Sheet 1 G ya/M @513 1W attozmeag Oct. 29, 1929.

A. JOHA NSEN SWITCH MECHANISM FOR TESTING TRQNSFORIERS :s sheets-sheet 2.

Filed June 7 28, 1927 Oct. 29, }929. A. JOHANSEN I SWITCH MECHANISM FOR TESTING TRANSFORMERS Filea June 28, 1927 3 Sheets-Sheet. 3

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Patented Oct. 29, 19 29 ANDREW JonANsnn, or BROOKLYN, NEW YORK SWITCH MECHANISM TESTING TRANSFORMERS Application filed June 28,

This invention relates to a switch mechanism for testing oil cooled transformers on high tension lines. The terminals of such transformers and of the feeder cables therefor are usually contained within an oil filled container called a pothead. When the feeder cable is to be tested, it is necessary to empty the pothead to get at the terminals and disconnect them from the transformer. This is a timeconsuming as well as a dangerous operation because the operators are compelled to work in close proximity to the terminals.

The object of my invention is to provide a switch mechanism whereby the'disconnecting of the transformer from the feeder cable may be done from outside the pothead without necessitating draining the same. Another object of the invention is to arrange the switch mechanism in such a manner that the operation may be performed at a point remote from the pothead and without requiring the workmen to operate directly on or with the transformer or feeder cable terminals. Still another object of the invention is to provide testing apparatus in a more compact and practical manner than heretofore. Other objects of the invention will appear as this specification proceeds.

In some'respects this application is. a continuance of or further development of the inventions of similar character disclosed in my pending patent applications Serial Number 102,099, filed April 15, 1926, and Serial Number 112,435, filed May 29, 1926.

'Accordingly myinvention is embodied in a switch mechanism or device arranged and constructed as hereinafter set forth and as illustrated in the accompanying drawings in which Fig. 1 is a sideview of a transformer and pothead embodying the invention with parts broken away and details .omittedt h Fig. 2 is a'front view of the pothead with the front wall removed and parts in section.

5 Fig. 3 is adetail view showing some ofthe parts in a certain operating position.

Figs. 4, Band 6 are similar views showing a modification.

Fig. 7 is a sectional side view of the'pothead and the improved testing mechanism.

1927. Serial No. 202,015.

Fig. 3 is a front view thereof.

Fig. 9 is a detail view of the operating carryswitch clips 8, connected to said transformer terminals.

The terminal supports 5 carry conducting bearings 10 in which switch blades 9 are mounted on an operating shaft 12. The latter has nonconducting portions 13 so that the switch blades serve to connect the feeder cable terminals 4 to the transformer terminals 6 1n parallel in an obvious manner. I-

believe it to be broadly new to connect the transformer and feeder cable phases by means of movable switch blades within the pothead.- Heretofore said terminals have been connected by. rigid connecting bars, or the feeder cable terminals have been connected directly to the transformer terminals.

In the top of the pothead there is mounted from the transformer. The testing appara-"' tus and devicesiare then connected in various manners to the three disconnected and exposed feeder cable terminals. In the present instance the connectors 14 serve as terminal connectors for the feeder cable terthree terminal connectors each of which conminals. To this end means are provided one end of the shaft is extended to the outside, through suitable stuffing boxes, and carries an arm connected by a link 21 to an operating arm 22 pivoted in any suitable manner at 23. 24 is a handle and by means 5 of a pin 25 passing through a hole in the arm 22 and correspondin holes 26 in the support 27, the arm 22 may be placedin two definite positions .in an obvious manner.

The parts are shown in their normal posim tion in Figures 1 and 2. When, however, it is desired to test the feeder cable, the latter is disconnected from, the transformer by moving theoperating arm into position 28, indicated in dotted lines. Consequently the 5 shaft 12 is rotated and the switches 9 are opened and swung over into the position shown in Figure 3, from which it appears that each switch blade engages the connector clip 16. As a result, the connectors 14 now become outside connector terminals for the feeder cable terminals 4. The operating arm 22 is now fixed in testing position by means of the pin 25. To insure that the blades 9 engage the connector clips 16, the blades may have suitable heel stops 29 which limit their movement in an" obvious manner.

The feeder cable is now ready for testingin precisely the same manner as heretofore 30 practised. In Figure 2 the elements 30 denote the wires leading from whatever testing apparatus is to be used. The connector caps 18 are opened or removed-after which the test wire terminals 30 may be inserted in the sockets 17 for testing purposes. The tests need not be described because no change is made therein nor in the testing apparatus. When the testing is completed, the switch blades 9 are swung back into normal closed position as is obvious. In the modification'illustrated in Figures 4, 5 and 6, the shaft 12 is eliminated and the switch blades 9 are individually pivoted in the conducting bearings 10. In this case therefore there are separate openings and closing means for the switches.

The switches are opened by a non-conducting opening bar 32 in the form of a yoke which is pivoted in the pothead on each side at 33. On the'one side the opening bar is extended outside the pothead and carries an arm 34 connected by -a link 35 to an opening arm 36,,Which is held in normal upper opening' position by a pin 37 engaging the support; 38. When it is desired to open the switches and connect the feeder cable terminals 4 with the connectors 14, the pin 37 is detached and the arm 36 swung down thereby moving the opening bar into the position 00. shown in Figure 6. The switches are stopped in proper position bythe heel stops 29. The

' operator feels in the arm 36 when the switches are fully opened and he thereafter moves the opening-bar back into normal inactive posi- After the testing the switches are closed by a non-conducting closing bar 40 also in the form of a yoke pivoted at 41, 41 in the sides of the pothead and operated by an arm 42 connected by a link 43 to an operating arm 44 which rests in normal inactive position on a stop 45. The operator swings arm 44 upward until he feels that the switches have engaged the transformer terminal clips 8. He then drops the arm 44 back into normal position.

The construction shown in Figures 4, 5 and 6 has the advantage of more positiveoperation in the opening and closing of the switches, and greater care in conducting thev operations by two separate operating arms. In the modification shown 1n Figures 7, 8

and 9, the invention is still further developed in that the pothead is arranged for testing in combination with a testing box of novel conception. Testing as practised in the art is done with'several different sets or pieces of testing devices, such as a grounding board or box, a lamp set or box and so forth. This invention provides a means for mounting the several parts of the testin apparatus on one panel in a box which maybe mounted on the pothead direct or remote therefrom. Referring to Figures 7 and 9, the switches 9 are mounted within the pothead in precisely the same manner as described in connection with Figure 1 and'the parts are numbered correspondingly. The non-conducting shaft 12 is extended outside the pothead and operated by means of an arm 50, a link 51 and another arm 52 adapted to be moved into three different predetermined positions by means of a pin 53 adapted to engage three holes 54 in a support 55 in an obvious manner.

panel to the poles 59 of a three-pole double throw switch 60.

The switch 60 is adapted to be connected to the one side with three switch clip terminals- 61 connected to removable testing links 62 which are grounded at 63. When thrown to the. other side, the switch 60 engages clips 64 connectedto three testing .lamps 65 connected in parallel to the pole of a single double throw switch 66. The latter is adapted to ground the lamps by engagement with aterminal clip 67, or it may be thrown to the other side to engage a terminal 68 of a live positive wire 69.

When it is desired to test the feeder cable, the switch 60 is closed on terminals 61 and 1 the arm 52 ismoved into position 7 O in Fig-.

On the front wall ofthe pothead and suiture 9, This movement causes the switches 9 to engage terminals 56, hence the feeder wires 4 are grounded and the operator ascertains whether the feeder is dead or alive. If the feeder is dead, nothing happens. If the feeder is alive the'groundmgjhereof will cause a flash, the circuit breakers at the central switchboard will open, an alarm will be sounded and so forth the same as occurs with the present testing sets. By removing the links, it is also apparent that each phase of the feeder cable may be tested by ground ing. Without going further into details about the tests themselves which are no part of this invention it is obvious that when the switches 9 are closed on 56, and grounded through the switch 60 and the links 62 removed, the terminals at 71 become outside ter minals of the feeder cable and accessible for testing,

For other tests, the switches 9 remain closed on terminals 56, but the three pole switch is thrown to the lamp side of the panel. If now the single pole switch 66 is thrown to ground at 67 and the operator at theother end of the line sends current through one of the phases, the particular lamp will light up if the phase is correctly connected, otherwise not. Similarly, other tests such as the loop test, phase identifications test, and so forth, are easil and quickly made by means of the testing box 57 and they need not be described.

WVhen the operating arm 52 is moved into position 72, the switches 9 engage the connector clips 16, and high potential tests may be made by inserting the ends of the testing wires in the connectors the same as described above. When the arm 52 is in position 74, the switches 9 again connect the feeder and the transformer.

It will be seen, therefore, that with the construction shown in Figures 7, 8 and 9, a very simple and practical testing device is pro vided for quickly and conveniently making the several tests. The test box-57 need not be mounted on the pothead but may be located a distance therefrom, or be portable, in which case of course the terminal clips 56 within the pothead will be connected by suitable cables to the switch terminals 59 in an obvious manner and not shown.

t From the foregoing it will be apparent that my invention provides means for disconnecting the feeder cable from the transformer without opening the pothead, and that the work of testing may be done without the workmen being compelled to operate directly on the several terminals, then eliminating a very dangerous feature of the work.

The construction and installation of my improvedv testing apparatus is inexpensive and easily made. Its operation does not require any greater skill than is necessary with the devices'heretofore used.' It will further be apparent that the invention lends itself readily to such modifications and changes as may be required for local purposes and without departing from the spirit of the in side of the pothead, connectors for testing purposes mounted in the wall of the pothead, switches within the pothead mounted on the feeder cable terminals and means outside the pothead for operating said switches into one of three different positions, viz, connecting the feeder cable terminals to the transformer terminals, or to the said connectors, or to thesaid switch terminals at will.

2. A swich mechanism of the character described comprising in combination a closed container, a plurality of pairs of terminals within the same, switch blades connecting each pair of terminals, a connector for each pair of terminals extending from outside the container to within the same, a

7 switch opening bar within the container for disconnecting said switch blades from the one terminal in each pair and connect said,

switch blades to the said connectors, means remote from said container for operating said opening bar, a switch closing bar for disconnecting the switch blades fromthe connectors and again connect them in each pair of terminals and means remote from the container for operating said switch closing bar.

ANDREW J OHANS-EN 

